The invention relates to a capacitive rotary encoder having a stator and a rotor as well as stator electrodes firmly arranged at the stator on an encoding path coaxial to the rotor axis, and coupling electrodes arranged at the rotor.
In this context, a rotary encoder is understood as a rotation-angle sensor or also as an angular position sensor. Typical applications of rotary encoders in the vehicle are steering-angle sensors or wear-free rotary switches.
Optical encoders which are expensive due to the use of optoelectronic components are known. Capacitive encoders with analog encoding are furthermore known (U.S. Pat. No. 5,736,865 A1), in which the accuracy highly depends on the quality of the signal path. In a further known capacitive encoder having a shield electrode (U.S. Pat. No. 6,892,590 B1), a coupling electrode floating in terms of potential leads to a high self-capacitance making signal evaluation more difficult.